A microscopic examination of silicone impressions of the perforations of beads, sealstones, and amulets has produced a data base of characteristics that help to define what type of drill was used to make them. This article outlines the various types of drills that have been used from the Palaeolithic period to the present day, and notes what microscopic features characterize each one. Scanning electron micrographs illustrate the minute details that are revealed by the silicone impressions.
The Society of Bead Researchers is a non-profit scientific-educational corporation founded in 1981 to foster historical, archaeological, and material cultural research on beads and beadwork of all materials and periods, and to expedite the dissemination of the resultant knowledge. Membership is open to all persons involved in the study of beads, as well as those interested in keeping abreast of current trends in bead research.
Gwinnett, A. John and Gorelick, Leonard
"A Brief History of Drills and Drilling."
BEADS: Journal of the Society of Bead Researchers
10: 49-56. Available at: